Cytologically proved malignant pleural effusions.

We read with interest the report by Assi and colleagues1 on the distribution of transudates and exudates between cytolog¬ ically proved malignant pleural effusions. The authors found that one of the 98 patients with malignant pleural effusions enrolled in the study, had a borderline transudate and had congestive heart failure at the time of the thoracentesis. The authors concluded that cytologically positive pleural effusions for malignancy are always exudates and that cytologic evalua¬ tion for malignant cells of a transudative pleural effusion is not recommended.